Engine starter meshing means



April 30, 1951 Q METSGER 2,548,268

ENGINE STARTER MESHING MEANS 2 Sheefos-Sheei; 1

Filed Nov. 13, 1947 IOA 62A INVENTOR.

L'HHRLEE 5. M57555? April W, 1951 c. s. METSGER 2,548,263

' ENGINE STARTER MESHING MEANS Filed Nov. 15, 1947 2 Sheets-Sheet 2 I348 6s v INVENTOR.

" RNEY- Patented Apr. 10, 1951 UNITED STATES PATENT OFFICE ENGINE STARTER MESHING MEANS Application November 13, 1947, Serial No. 785,723

Claims. (Cl. 123-179) The present invention relates to engine starters, and particularly to a starter of the selfcontained high-speed. type, in which the turning motion is transmitted through a rotatable output member or jaw having its axis of rotation in line with the axis of rotation of an engine member.

Among the objects of the invention are to provide a starter structure or system of greatly increased power and reduced weight as for aircraft service and which shall avoid the disadvantages of overrunning clutches, such as destruction of parts by centrifugal force upon failure of operation, completely separate the high speed meshing starter and engine members,- reduce critical tolerances, mesh the starter and engine members prior to a given rate of operation of the starter, and have other advantages.

Another object is to provide a device of the above-indicated character which shall be simple and durable in construction, economical to manufacture, and efiective in its operation.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the accompanying drawings wherein three embodiments of the invention are illustrated by way of example.

In the drawings:

Figure 1 is a diagram of a system including a view in section of a starter of the invention;

Figure 2 is a bottom detail view of a portion of the structure of Figure 1;

Figure 3 is a view in side section, parts broken away, of the invention in modified form;

Figure 4 is a fragmentary detail of a modified portion of Figure 1; and

Figure 5 is a side view generally in section, but having parts in elevation, of another form of the invention, and including a diagram of parts associated therewith.

The structure of Figure 1 comprises a rotatable engine-engaging member Ill adapted for axial extension and retraction movements, respectively, between a position released from, and a position meshed with, an engine member I2 for starting the engine, the member it being shown in the released position. The device further comprises an axially stationary rotative nut M,

means including driving means [8 adapted to rotate the nut l4, a screw shaft element 29 axially movable relative to, and rotatively movable by, the nut I4 associated with the engine-engaging member H] for rotating the latter. A meshing rod element 22 is adapted to move the engineengaging member I i in its axial extension move- 2 ment engaging it to the engine member l2, -the members in and I2 being of the male and-female spline type, respectively having interfitting splines or teeth.

Means including spring means 26 cooperate with the meshing rod 22 to oppose the movement of the engine-engaging member 1!! by-the rod. Means 28 is adapted, in this instance, to effect the movement of the element 22 through the intermediary of a yieldable or fluid medium such as steam, for example. Throttle means 34 provides for first initiating movement of the rod element 22, and following with rotative action of the engine engaging member ill by the driving means l3.

The driving means I8 comprises a partition 36 in a housing 38 and, with the latter defining a pressure chamber 4!] adapted to contain a catalyst for hydrogen peroxide, such as manganese dioxide, copper, and silver. The partition 36 is provided with nozzles 42 for operating a turbine rotor 44 mounted on a sealed bearing 46 supported by a cylinder 48 carried by the housing 38 therein, the latter of which is provided with exhaust parts 39.

The spring means 26 is disposed around the rod 22 in the cylinder 48, and acts between one end of the cylinder, and a head or piston 56 at one end of the rod for biasing the latter to the position shown, corresponding to the retracted position of the member ID. The other'end of the rod 22 is connected to the inner race of a ball-bearing" 52 having its outer race connected to the screw shaft 20 therein, so that the latter may be moved axially by, but rotate relative to, the plunger. Y V I The rotor 44 carries a plate 54 including a stub shaft portion 56 journaled in a bearing 58 in a partition 69 of the housing 38 and having a pinion or sun .gear 62 meshing with planet gears 64 which mesh with rotatably yieldable axially adjustable toothed discs of a torque limiting disc pack 66, the alternate discs of which are axially adjus'tably, but non-rotatively, held to the housing 38. The discs of the pack 56 are adjusted relative to each other, as by a belleville spring 6'! and a ring nut 59. The rod 22 extends loosely through a bore in the portion 56 and the gear 62.

The planets 54 are journaled on a carrier 68 constituting part of the nut l4, which is journaled in bearings 10 mounted in the housing 38.

The means 28 comprises a source 12 of propellant, such as hydrogen peroxide, communi- A motor 86 for driving the pump I6, is fed by conductors 88 from a source of energy 90 and controlled by a switch 92, which, in this instance constitutes the starting switch.

In operation, with the parts of Figures 1 and 2 in the positions shown, closing of the switch 92 energizes the motor 86 to operate the pump I6, which causes propellant irom'the source I2 to flow through the pipe I4 to the pump and from the latter under pressure through the pipe I8 to the cylinder 48.

The pressure of the propellant initiates movement of the piston 50 to the right from its retracted position, as shown to initiate movement of the rod '22, after which the piston opens the slit 82 to, at first, admit reduced flow of propellant to the chamber 4|]. This action generates enough steam pressure by the hydrogen peroxide breaking up into oxygen and water in the form of steam upon contact with the catalyst to rotate the turbine slowly until the piston passes the right-hand end of the slit B2 and starts to efiect gradually increased flow of the propellant to the chamber 40 by reasons of the enlarged or diverging portion 84 of the aperture 80. Continuation of the action, from the right end of the slit 82, causes the member II] to engage the member I2 before the rotation of the member III attains a predetermined rate such that, if the member I0 butts, instead of immediately meshing with the member I2, it will be turned to meshing position, and meshed under the continued thrust by the piston 50.

Compressed air or other gas may be substituted for the propellant and catalyst arrangement of Figure 1, each form having advantages over the other, for certain applications.

As indicated in Figure 4, the engine-engaging spline member ID of Figure 1 may be replaced by a usual jaw 94 for meshing engagement with a jaw corresponding to the engine member I2.

The structure of Figure 3, in which certain corresponding parts are designated by corresponding reference characters having the suffix a, is adapted to obtain results similar to those of the structure of Figure 1 in general principle, if not in scope, by electrical means.

As in Figure 1, the device of Figure 3, comprises a rotatable engine-engaging member I 0a adapted for axial extension and retraction movements respectively between a position released from and a position meshed with an engine member (not shown), corresponding to the member I2, for starting the engine. The device further comprises an axially stationary rotative nut I4a, means including driving means IBa adapted to rotate the nut Met, a screw shaft element a axially movable relative to and rotatively movable by, the nut I40, associated with the engineengaging member Ina for rotating the latter. A meshing rod element 22a is adapted to move the engine-engaging member Illa in its axial extension movement engaging it to the engine member.

Means including spring means 26a, cooperates with the meshing rod 22a to oppose the 111.9%,-

4 ment of the member nm by the rod. Means 28a is also adapted to effect the movement of the element 22a through the intermediary of a yieldable medium which, in this case, is a spring 32 which is very much stiffer than spring means 26a. Means 34a corresponds to the throttle means 34 of Figures 1 and 2 in that it provides for first initiating movement of the rod element 22a, and following with rotative action of the engine-engaging member Illa by the driving means I811.

The driving means I8a, of Figure 3, comprises a motor 96 including an armature 98, corresponding to the rotor 44 of Figure 1, a shaft I00 journaled by a bearin I02 in a partition 60a of a housing 38a and having a sun gear 620, meshing with planet gears 64a. The latter mesh with rotatably yieldable axially adjustable toothed discs I 12 of a torque-limiting disc pack 66a, the alternate discs I I4 of which are axially adjustable but non-rotatively held to the housing 38a, the discs of the pack 66a also being adjusted relative to each other, as by a belleville spring 61a and a ring nut 69a. The rod 22a extends loosely through a bore H6 in the shaft I and the sun gear 62a.

The planet gears 64a. are journaled, as by bearings H6, on a carrier 68a constituting part of the nut l4a, which is journaled in bearings 10a mounted in the housing 380,.

The means 28a comprises a lever I I8 pivotally mounted relative to the housing 38a, as by a pin I20, and having a short arm I22 and a long arm I24, the latter of which has an end I26 adapted to cooperate with a head I28 of the meshing rod 22a to push the latter to the right against the action of the spring 26a. 7

The means 28a further comprises an electrical unit I29 including a solenoid coil I30 surrounding a hollow armature core I32 carrying a plunger I34 axially movable relative thereto, which plunger has a head I36 normally held against a seat I38 of the core by the yieldable medium or spring 32, and which spring is backed and held in place, as by a locking ring I40 in a groove of the armature core I32. Downward movement of the core I32, as shown, is limited by stop means I42. A belleville spring I43, movably carried by the plunger I34, in this instance constitutes a bridging contact member for stationary contact elements I44 adapted to be connected in the circuit of the motor 96.

In operation, with the parts of Figure 3 in the position shown, when the circuit of the solenoid coil I30 is closed, the core I32 descends, carrying the plunger I34 and the spring 32 with it, while retained in the relative positions shown. If the engine-engaging member Ina meshes immediately with the engine member, the action of meshing will be carried straight through with the plunger I34 and the spring 32 retained throughout the action in the abovementioned relative position during which the bridging contact member I42 bridges the stationary contact member I44 to close the circuit of the motor 36. However, when the member Illa butts the engine member, the downward motion of the plunger I34 stops, while the downward motion of the solenoid core I32 continues against the action of the spring 32 such that, when the contact member I42 bridges the stationary contact member I44 to energize the motor 96, rotation of the armature 98 will cause nut Me to rotate and thereby by means of the threaded engagement thereof with screw shaft element 20a will cause mes the member Mic with the en in member before the rotation of the member I00. attains a predetermined rate of speed.

The structure of Figure 5, now the subject matter of divisional application Serial No. 167,778, filed June 13, 1950, in which certain corresponding parts are also designated by corresponding reference characters having the suffix b, is also adapted to obtain results similar to those of the structures of Figures 1 and 3, in general principle, if not in scope, by the use of compressed gas and rotative driving means of any desired character, such as the rotor of a turbine or the armature of an electric motor.

As in Figures 1 and 3, the device of Figure 5 comprises a rotatable engine-engaging member I017 adapted for axial extension from and a position meshed with an engine member (not shown) corresponding to the member I2, but ofthe jaw, instead of the spline, type, for starting the engine. The device further comprises an axially stationary rotative nut I417, means including driving means I8b adapted to rotate the nut I412,

a screw shaft element 20b axially movable relative to, and rotatively movable by, the nut I4b associated with the engine-engaging member I0b for rotating the latter. The screw shaft element 20b, instead of the rods 22 and 22a of Figures 1 and 3, respectively, or of the rod 221) of Figure 5, is adapted to move the engine-engaging member b in its axial extension movement engaging it to the engine member.

Means including spring means 26b cooperates with the meshing rod 22b to oppose movement of the member I0b by the screw shaft b. Means 28b is also adapted to effect the movement of the screw shaft element 201) through the intermediary of a yieldable medium, which in this case is compressed air.

Means 34b corresponds to the throttle means 34 of Figures 1 and 2, and the means 34a of Figure 3, in that it provides for first initiating movement of the screw shaft element 201), instead of the rod element 22b, and following with rotative action of the engine-engaging member I0b by the driving means I81).

The driving means I811, of Figure 5, comprises -a plate I adapted for attachment to the rotor of a turbine or other motor, and provided with a female spline extension I52 adapted to receive a cooperating male spline shaft I54, journaled by a bearing I56 in an end plate I58 of a housing 38b. The plate I50 is held axially relative to the shaft I54 between the bearing I56 and a nut structure I60 in a cavity of the extension I52.

A portion I62 of the housing 38111138 a chamber I64 in which is disposed a flange I66 of the shaft I54 which is secured, as by a ring I68 and screws I10, to a closed end wall I12 of a barrel I14 journaled in the housing portion I62 as by bearings I16.

The spline nut I4b, in the barrel I14, is connected to the latter by a torque-limiting friction disc pack I18 having interlayered discs fixed to the nut I41) and the barrel I14, respectively, and axially biased together, as by helical springs I80 anda ring nut I82 threaded in the opposite end of the barrel I14..

The screw shaft 2%, having long-lead thread relation to the nut I41) therein, has an axially slidable spline connection I84 to the starter clutch jaw member I0b.

and extending through an aperture in the jaw I0b, which aperture is closed by a'seal I88 biased against the jaw by a spring I90 extending into the screw shaft 202). A nut I9I is mounted on the rod 22b at the left of the jaw I0b.

The screw shaft'20b is limited in its axial movement to the right, as viewed in the drawing, by engagement with a disc I92 against the barrel end wall I12 and, in its axial movement to the left by a usual shoulder on the screw shaft 20b with a shoulder on the spline nut I4b. A ring seal structure I94, not germane to the present invention, cooperates between a bafile portion I96 of the housing 381) and the jaw member I017.

The screw shaft 20b, instead of being for advancement by rotation of the nut I 4b as ina usual direct-cranking starter having, friction means adjacent to the seal I94, the latter of which is not true in this case, is adapted as by seal rings I98 and 200 in grooves of the screw shaft around the rod 22b and the shaft 20b,respectively, for action as a piston responsive to fluidpressure introduces into the chamber I64.

An inlet 202 admits fluid to the chamber I64 for passage, indicated by arrows, through passageways 204, 206 and 208, see lower central portion of the figure, to the screw-shaft-piston 20b.

The means 28b comprises an electrical unit 2l0 corresponding to the unit I29 of Figure 3, with the exception that a plunger I341) corresponding to the plunger I34 of Figure 3, instead of being adapted to push a lever, such as the lever IIB, has its lower end constructed as the movable element of a valve 2I2 for controlling the flow of fluid, such as compressed air, form a source 2I4 through a pipe 2I6, the valve 2I2 and a pipe 2I8 to the inlet 202.

Means 34b corresponds to the throttle means 34 of Figures 1 and 2, and to the means 34a, of Figure 3, in that it also provides for first initiating the axial extension movement of the screw shaft element 20b, during which, prior to rotation of the shaft I54, the element 281) will rotate, but not under the power of the shaft I54.

A device 220 corresponds either to a motor such as the motor 86a, the motor 96, or as in this instance, another electrical unit, such as a solenoid, for starting a turbine, and is controlled as by a switch 92b relative to a source of electromotive force 90b.

In operation, with the parts of Figure 5. in the inactive positions shown, when the switch 921) is closed, current flows from one side of the source 901) through a conductor 222, the switch 92b, the solenoid coil I301), of the unit 2I0, and a conductor 224 to the opposite side of the source 9012. This action, first opens the valve 2I2 to cause flow of fluid from the source 2I4 through the pipe 216, the valve 2I2 and the pipe 2I8 to the inlet 202, and into the chamber I64. From the latter, the fluid flows, as indicated by arrows, through the passageways 204, 206, and 208 to the rear of the piston screw shaft 201), to advance the latter to the left and to push the member I01), through the intermediary of the spring means I80, into engagement with the, engine member,

' duringwhich the shaft 201) will rotate in the stationary unit Mb to rotate the member I012. The timing of the opening of the valve 2l2 and the closing of the circuit of the device 200 is, in this instance such that the shaft piston 20b will cause the rotating member I01) to engage the engine member before driving operation of the shaft I54. Thus, the member lfibhas a chance to mesh before theapplication of rotative power. If, however, butting should occur, meshing will be insured upon the first application of rotative driving power, prior to the attainment of a certain rate of speed by the member lllb.

The timing aforesaid may be varied such that power rotation may be applied upon, or at any time before or after, engagement of the member "1b with the engine member as desired or dependent upon conditions of, or circumstances surrounding, a particular case.

Although each form of the invention, as stated above, operates on substantially the same broad general principle as the others, the differences in scope or application allow wide divergencies of application, manufacture, assembly, cost, size, weight, materials, repair and almost every conceivable factor which may be associated therewith.

For instance, the device of Figure 1 may pro vide substantially greater power for a given weight than the device of Figures 3 and 5, thus making it more effective for certainbranches of aircraft practice, while the devices of Figures 3 and 5 may be better suited in other branches from the standpoint of cost, replacement, repair or other considerations. The device of Figure 5 has the-advantage over the other forms of immediate utilization of standard parts of former starters not previously operable in the same manner.

The invention therefor provides for a very great range of its application and uses, and is an improvement generally in its field.

Although only three embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.

What is claimed is:

1. In an engine starting mechanism, the combination of a rotatable engine-engaging member adapted for axial extension and retraction move ments, respectively, between a position released from, and a position meshed with, an engine member for starting the engine, an axially stationary rotative nut, means including fluid-responsive driving means adapted to rotate the nut, a screw shaft element axially movable relative to, and rotatively movable by, the nut and associated with the engine-engaging member for rotating the latter, a meshing rod element, one of said elements being operable by fluid pressure to move said engine-engaging member in its said axial extension movement engaging it to said engine member, means including spring means cooperating with said meshing rod element to oppose said movement of the engine-engaging member by said one element, a pressure chamber containing a catalyst associated with said fluidresponsive driving means, a source of propellant, means adapted to convey the propellant under pressure from said source to said one fluid-pressure operable element for first operating the same to initiate said extension movement, and a throttle device including means controlled by said one member for startingthe engine, an axially stationary rotative nut, means including fluid-rev sponsive driving means adapted to rotate the nut, a screw shaft element axially movable relative to, and rotatively movable by, the nut and associated with the. engine-engaging member for rotating the latter, a meshing rod element, one of said elements being operable by fluid pressure to move said engine-engaging member in its said axial extension movement engaging it to said engine member, means including spring means cooperating with said meshing rod element to oppose said movement of the engine-engaging member by said one element, a steam pressure generation chamber associated with said fluid-responsive driving means, a source of fluid pressure, means adapted to convey fluid from said source to said one fluid-pressure operable element for first operating the same to initiate said extension movement, and a throttle device separate from and including means controlled by said one fluidoperable element to admit said fluid to said chamber for the generation of steam to cause rotative action of said engaging member by said driving means following the initiation of said extension movement.

3. In an engine starting device, the combination of a rotatable engine-engaging member adapted for axial extension and retraction movements, respectively, between a position released from, and a position meshed with, an engine element for starting the engine, a meshing rod element, fluid-actuated means adapted to actuate s'aid meshing rod element to efiect said extension movement, fluid-responsive rotatable means adapted to rotate said engine-engaging member, a pressure chamber containing a catalyst associated with said fluid-responsive means, a source of propellant, means adapted to convey propellant from said source under pressure to said fluidactuated means for operating the same to eflect said extension movement, and throttle means controlled by said fluid-actuated means to admit 'the propellant to said chamber for reaction with the catalyst causing fluid pressure for operating said fluid-responsive means.

4. In an engine starting mechanism, the combination of a rotatable engine-engaging member adapted for axial extension and retraction movements, respectively, between a position released from and position meshed with an engine element 'for starting the engine, an axially stationary rotative nut, driving means adapted to rotate the nut, a screw shaft element axially movable rel-altive 'to and rotatively movable by the nut and associated with the engine-engaging member for rotating the latter, a meshing rod element, said meshing rod element being adapted to move said engine engaging member in its saidaxial extension movement engaging it to said engine element, spring means cooperating with said meshing rod element to oppose said movement of the engine-engaging member by said meshing rod element; a first power means including a fluid pump for supplying a fluid medium under pressure'to actuate said meshing rod element in opposition to said spring means, a second independent power means including a steam generator and a turbine driven by the steam from said generator to effect rotation of said nut through said driving means, and control means operated by said first power means for initiating operation of said second power means and rotative action of said engine-engaging member by said driving means following initiation or the axial extension movement of the engine-engaging member by said first power means so that said first and second power means coact to complete meshing of the engine-engaging member with the engine element.

5. In an engine starting mechanism, the combination of a rotatable engine-engaging member adapted for axial extension and retraction movements, respectively, between a position released from and a position meshed with an engine element for starting the engine, an axially stationary rotative nut, driving means adapted to rotate the nut, a screw shaft element axially movable relative to and rotatively movable by the nut and associated with the engine-engaging member for rotating the latter, a meshing rod element, said meshing rod element being adapted to move said engine-engaging member in its said axial extension movement engaging it to said engine element, spring means cooperating with said meshing rod element to oppose said movement of the engine-engaging member by said meshing rod element; a first power means including a source of hydrogen peroxide, a fluid pump for supplying said hydrogen peroxide under pressure from said source to actuate said meshing rod element, a second power means including a chamber for decomposing the hydrogen peroxide to steam, a turbine driven by the steam from the decomposing REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,778,900 Lansing Oct. 21, 1930 FOREIGN PATENTS Number Country Date 515,753 Great Britain Dec. 13, 1939 551,073 Great Britain Feb. 5, 1943 575,507 France Apr. 23, 1924. 

